Mouthguard storage box



FIG. 1 is a front perspective view showing my new design;

FIG. 2 is a right side elevational view, which is a mirror image of the left side;

FIG. 3 is a bottom plan view;

FIG. 4 is a top plan view;

FIG. 5 is a front elevational view; and,

FIG. 6 is a rear elevational view.

The broken line drawings of a belt clip are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a mouthguard storage box, as shown and described. 